I do like the game, however at one point I lost interest -- specifically after losing 5 times in a row after the first checkpoint. Being used to casual easy to pickup games, feels like the difficulty curve is a but too high too fast.
That said, if you make the players more engaged before upping the difficulty, the game will improve as a whole.
So maybe make a few more platforms in the beginning that have blocks preventing you from slipping? Enabling the players to get a feel of the physics before making them fall to their flamy death.
Why is it so dark? I was under the impression that the game is faded out and paused, but it was actual gameplay.
Really, really dark. Or is that a bug?
While this has been done before, the level design in the later levels literally bends your mind. This game is best judged on latter levels -- and it's totally awesome. Don't tempt yourself into using the walkthrough.